You've made me paranoid about my car now mate haha!
It's clean as a whistle under boost, no smoke at all but when engine is cold I get a bit of a siren noise. Although my power doesn't spike.
I know what the guy means about the loose connection to rubber hose on the forge pipe (behind head lamp) I had to really clamp down on to mine but there's no issue, it's because the pancake pipe requires some real persuasion to remove and I think the rubber pipe stretches a bit
I will have to fit the pipe myself then, he said it might be a case of buying some more silicon to do it with. I wouldn't worry about the turbo noise, or you would never enjoy driving the car. Mine would whine a lot, to the point where passengers would say "there's a police car coming I think" or "where's that ambulance?" Mine used to smoke a lot but there is barely anything now, I guess because everything is nice and clean and soot free for now